Radjet 800. First Flight.

...back better than ever

The arrival of the Radjet, my second and a replacement for the much loved and even more battered original, was much anticipated. The pretty original had been the subject of countless crashes as I struggled to learn the secret of getting it into the sky.

Along the way I learned about the delicate balance required with speedsters, and not to get the Radjet into flat spins form which it struggles to escape. I also learned, and relished in, the Radjet's capacity for rock-solid performance and high-speed stability.

My arrival of MkII caused some angst as nearly a year had elapsed since it's predecessor had retired after the incident with the sapling. Fortunately, and remarkably, my lessons learned were so entrenched that the pretty speedster launched and flew virtually perfectly.

Something that I never had the opportunity to appreciated before it was pummeled through launch training, was just was cleanly the Radjet flies, swift cruise at half throttle and effortless acceleration out of dives.

So, despite the nervous anticipation, the Radjet is back and reinforces my perception that this must be one of the best-value foam speedsters around...

Radjet 800 Unboxing

...what's in the box

The Radjet comes nicely poackaged - double-boxed with all items individually wrapped in plastic, so there's no damage.

The parts are nice-quality EPO, and the kit also includes an underside protector skid. The canopy is a loose moulded plastic part which needs to be attached to the base, which includes magnets for attachment.

This kit, the PNF, includes a pre-installed 1850kv motor, and a 20A speed controller, good for 100-120kph performance with a 4S battery.

All parts fit neatly together, with the tail & wings needing to be glued. Note that you'll have to add some sort of reinforcement to the wing joins, preferable some sort of spars or strips because the basic joint isn't going to cope with the wing loadings of this pretty speedster...

Radjet 800 EPO. Paddock Flypasts

...fast fun

Breezy afternoons don’t suit too many planes; of mine the pick are the Rarebear, Stinger and Radjet. This particular afternoon there was a fresh northerly blowing and I headed right into the paddocks, my favourite spot for speedy planes free of any obstructions making it great for low-level, high-speed flypasts.

I find the Radjet a very stable high-speed plane and able to handle wind with aplomb, so I had a great time speeding it upwind and downwind, always at full throttle as usual. Unfortunately, by the time I got to the fields this particular afternoon, the sky had got a little hazy causing glare.

As a result the video struggled a bit with the contrast and, although I tried to balance colours and lighting manually afterwards, it’s very difficult and the video still doesn’t look quite right.

Nevertheless, the flying is quite entertaining and the sky, although not as lovely as it had been earlier in the day, was still a lovely backdrop to the speeding Radjet...

Hobbyking Radjet 800. Sunrise.

...high-speed fun

The other morning I took the Radjet along with me. I hadn't flown it for a while so the launch is always a slightly tense affair, but my launch technique is still solid, with the Radjet launching into the growing sunrise. 

It's still pretty quick, although slightly off the pace when it was flying the little 850mAh nanotech, however it's quick, and stable enough that you can bring it over on super-low flypasts with confidence.

It was a most enjoyable flight and, as the battery died off, I turned the Radjet around for finals. The Radjet is surprisingly easy to land; with power off it is pretty floaty, and it glides in surprisingly easily.

Except this time when I had it headed into the tree behind me...

Radjet. New Look. Big Battery.

...good and not so good

The little 850 4S lipo that had served the Radjet well finally went to battery heaven which left me pondering what to do. However, with the Stinger in pieces under the table awaiting a new fuselage, the obvious option was to adopt that.

I'd flown the Radjet once before with the 1800 4S; it flew OK although the battery is a little oversized, and it also didn't quite fit in with the small hatch I'd made to fit the battery in with the Radjet's reconfigured nose.

So I made a second magnetic hatch, which allowed the big battery to be inserted with ease, being pushed into the front fuselage just enough to secure it and allow balance to be set.

As before, the extra weight shows, with the Radjet needing a little up-elevator trim to compensate. Also, although the battery has a 40C rating, it still doesn't deliver the kick that the little 45-90 nanotech does.

But the Radjet still flies well and, with its sleeker lines, isn't much off the pace. A bonus with the big pack is that the Radjet now flies flat out for longer...

Radjet Faster

...properly quick

As I suspected on the first flight, the Radjet with its made-over nose is now significantly faster, especially noticeable this afternoon when the weather was a little warmer than its test flight.

The Radjet flew nice and stably, although its extra few yards of pace mean that I'm still not a hundred percent comfortable, finding it going through the turns or sweeping down quicker than expected. I would now call it properly quick.

I also managed a better launch, with a higher angle and enough throttle to get the Radjet up to speed quickly. Having said that, I had to trim the elevators down even more as the Radjet was still climbing in flight, which means that the next launch will be another test.

The only hiccup in an otherwise flawless flight was that the motor stopped abruptly. Thinking that likely the ESC had given up the ghost, I tried the motor after a while and the prop spun to life.

I think it's probably the thermal cut-out and that the sleeker Radjet needs more cooling slots...

Radjet Test Flight Havoc

...but got there eventually

I took the Radjet to the field today for a test flight in its new sleek guise, a beautiful sunny afternoon with clear blue skies and a refreshing southerly breeze.

As well as the new nose, I had reset the Radjet's controls and checked servo throws as well as reducing the elevator trim I usually have as I reckoned the Airbus-like fuselage interface would generate lift in flight.

The first launch was a complete crash, with the Radjet nosing down as of old straight into the ground. I figured this was because of the lack of elevator trim, so dialled it back in again. The second attempt started well, with the Radjet climbing steeply into the sky as I craned my neck to keep track of it.

However, as I levelled the Radjet it suddenly went unstable and ended in a flat spin, the only thing I could do was put full aileron and full elevator which slows the descent of the plane still inescapably spinning.

Collecting the Radjet I reckoned I knew the cause; the plane was balancing on the fingertips but only in the centre of the grips; slide the fingers forward and the Radjet was tilting back. I had hoped this would be OK but proved this wasn't the case.

A solution to this was to re-orientate the receiver so that I could push it further forward in the nose, and shoved in a small stick, the only ballast I could find at hand. So, with the plane now balanced I went back for the third try.

Fortunately this time everything went to plan and the Radjet went careering into the sky. My guess about the new configuration generating lift was right, so I had to dial the elevator trim back to neutral. This levelled the flight, but means I'll have to figure out something for launch next time.

The Radjet seemed faster, and twitchier, the former certainly due to the sleek nose, while the latter I think is related and I've just increased the expo a few percent. So, the Radjet is back in the air at least, although not without some drama, and I'll have to do a little work figuring out the launch next time...

Radical Radjet Repair v2

...ready for more

I'd been flying the Radjet regularly with no launch issues when I somehow crashed it the other day, which was both annoying and disappointing. Looking at the mangled and oft-glued nose I decided to give it a radical repair.

So, on arriving home, I sliced off the mangled front fuselage and then waited for inspiration. Not many options came to mind as the Radjet sat on the desk looking disgruntled. In fact the only viable option was using a caulking tube, except that I could figure how to get it to fit.

Eventually I fitted the round tube around a wooden template to match the fuselage shape and heated it with boiling water, hoping that this would help to set the shape. I cut away the top section of the tube in the fuselage area to provide access for mounting hardware, and hot-melted it into place with a few small bolts through the fuselage to help keep it in place.

The lower section of the fuselage, where it used to meet up with the front, I tapered down as the caulking tube was much thinner than the EPO original.

The result I gave a broad silver stripe from the nose all the way down the fuselage, and bordered it with a black stripe for good measure. The result looks interesting but certainly better than before.

Hopefully I'll get it into the air soon and see how it flies; I'm hoping it'll be well as I've been missing blasting the Radjet around the fields...

Rarebear Slow Prop

...shows how good the original is!

I recently had a minor incident with the Rarebear; the result of me somehow reversing the elevator, probably while I was adjusting settings on the transmitter. The result was the Rarebear nosediving straight into the turf, although fortunately with the ground being very damp there, the damage was limited to a broken prop.

Unfortunately I'd used the last of my Funfighter props on the Radjet, which now uses the same propulsion system as the Rarebear.  The only alternative were some APC style props which I'd bought based on reviews, so I got one out the bag and fitted it to the Rarebear.

This morning, a lovely cool and calm start to the day, I took the Rarebear along to try it out.  Flying on the 3S 1300 battery the Rarebear is usually pretty quick, although manageable, so I was quite amazed at how much slower it was compared to flying with its original prop.

While you would think there wouldn't be much difference between a 6x4 and a 5.5 x 4.5, it just shows what a brilliant combination the original prop and motor are together...

Ride on a Radjet

...high-speed fun

For some while I've been meaning to get an on-board video with the Radjet but, given the weather and choice of planes on the day, I still hadn't got around to doing it. 

The Radjet it the fastest plane in the fleet, now running the Funfighter motor and prop as well as the mini 4S battery. It's also that plane which is flown with most abandon, given it's rock-solid behaviour in the air. It's twin-tailed configuration and bold markings also make tracking its orientation easy, so I'm always confident that I know what it's doing. 

My one concern was whether the camera, mounted just forward of the tail fins on the curve fuselage, would be secure enough, considering it was only in contact with a narrow strip of velcro. Consequently I was a little conservative in flying the Radjet and happily the Mobius was still there when the radjet touched down...

High-Speed Afternoon

...blue skies and beautiful clouds

Today was one of those days when the weather continually surprises you; this morning was heavily overcast and still, giving one the anticipation of a dull day, possibly even rainy. Then, looking out the window a little later, one is surprised with the grey dissolving into little patches of cumulus, feeding off the warming earth. And then, a little later still, the sky is almost clear and a cool afternoon is blowing, a gift from the Southern Ocean.

Although a little breezy, with such lovely weather I decided to make a turn past the field just in case, and happily found a steady and quite flyable breeze, especially as the car had a boot-full of little buzzies.

The recent smash, and possible destruction, of the Phoenix (now there's irony; perhaps I should set it alight as a shortcut to repairing it) has left me a little nervy to fly, especially the high-speed brigade, despite the crash not being pilot-related for once. Anyhow, the opportunity to get out and enjoy the lovely afternoon whilst the planes headed skywards towards the pure white clouds was too good to let go begging.

It was the first outing of the Stinger since its repair, following its three-day stay in the paddocks after it went MIA. While suffering only minor damage, test-flying something that's been repaired has potential to be heart-stopping. Fortunately, apart from a slightly hair-raising launch, largely as a result of me throwing it skew causing the Stinger to hang on knife-edge, it flew perfectly well.

Having not flown it for some while, however, I'd lost a bit of touch with its, well, touchy behaviour, and for most of the flight I felt as if I were courting disaster. Nevertheless, all went well and the Stinger ended up in a long glide in for a safe landing.

The Radjet, flights of which book-ended proceedings, once again enhanced its reputation as a solid high-speed platform, giving relatively effortless performances and outrunning the Stinger in most departments, except the distinctive jet whine and apparently effortless performance. I have, on a number of occasions, especially since I learned how to launch it properly, have considered getting a new Radjet kit, my rough-lived example bearing barely any resemblance to the original.

However, despite appearances, which would be desirable especially during low fast passes when its chequered past becomes more evident as it approaches, as it still flies remarkably well, and fast, trading it in for a replacement would seem like a rather poor deal for a faithful plane which wears the scars of lessons learned discovering how to actually fly it...

Radjet Test Flight with 4S 1800 Battery

...without disaster or mishap

This afternoon was gorgeous and sunny, slightly warm with a gentle breeze from the south west, perfect for letting the recently-refurbished Radjet loose with its boisterous battery pack, the 1800 4S 40C borrowed from the Stinger.

As mentioned previously, I'd had several concerns relating it being too heavy with the oversize battery or simply bursting into flames due to the ESC being overworked. Fortunately, neither happened, with the Radjet taking to the skies without incident and flying well.

I did a few circuits before bringing it down, needing to make a few adjustment to the elevator settings after the servo change, and also to dial in a little more expo with the new servos having a bit more travel than before. Having sorted out the details, I threw the Radjet up again to give it another run.

The battery, significantly larger than the recommended 1300 and substantially larger than the 850 I'd been using, is rather oversized for the power system and changes the characteristics of the Radjet into something of a grand tourer. I think a 1300 4S battery is probably the ticket, providing enough current and flight-time without carrying any excess.

So, while this exercise answered one nagging question, it also raised another; considering it can comfortably carry the 1800, what if you uprated the motor and the ESC...

Radjet with Big Battery

...and a servo upgrade

Following my conversion of the Radjet to give it a battery hatch for easier insertion of the chubbier 4S batteries, I was playing around the other day and discovered I could actually get an 1800mAh battery in without much effort. This was rather remarkable and something I had thought of doing before but never taken much further as I thought it unfeasible.

My concerns are that the sustained current supply from the larger battery might overwhelm the stock ESC, and the other that the additional weight might cause issues with the Radjet, especially on launch. Regarding the former, the 1800 is a 40C while the little 850 is a 45-90C, so I don't think there should be too much difference, except for duration. To hopefully reduce the heat-load, I have installed an extra cooling port (slurpee straw) directed straight onto the ESC and of course the Radjet runs without a canopy these days.

In the case of the latter, I think the Radjet should be OK with the mass, considering the Stinger runs with this battery on a smaller wing area and with a heavier body.

I've also replaced the original wing servos with Turnigy TG9z's due to these stripping when I pancaked the Radjet on its most recent flight. I'd bought these servos as the HXT 900's were out of stock and, while expecting much the same, I was amazed when first powering these up at how quiet they were in comparison. I gather these are not quite as strong as the HXT's, however they should are well rated and sound super-smooth!

So, since today was just way too windy from start to finish, I'm hoping that I might be able to get the Radjet into the air tomorrow and see how it goes...

The Big Chill

...airborne meditation

Following my efforts to get the Canadair airborne, and considering I only get two goes a week due to lake access, I've been chilling out flying the Phoenix, interspersed with a bit of high-speed fun flying the Radjet (aka buzzy jet )and Rarebear (aka little buzzy) around the paddock.

Having suffered reconstruction nerves, which saw the Rarebear nosediving on launch and the Radjet almost knife-edging into the lake, I've now got both of them launching most enjoyably.

The last couple of outings I have also been enjoying a little meditation with the Phoenix, climbing it hard till just under the clouds and then letting it float down slowly, hanging almost motionless in the air with the flaps down. Today, with winds gathering up high, the Phoenix was actually drifting downwind, almost imperceptibly, despite there being barely a breath of wind on the ground...

Radical Dude

...thats hot!

Following on from the successful motor transplant in the Radjet, I wanted to give its very-battered nose a bit of reinforcing, consisting as it did of fragments of foam superglued and bounded by tape, which basically holds everything together. Due to missing bits, however, superglue wasn't really working anymore, however I had a great idea - hot melt!

I have tried this out and it worked brilliantly - basically I have injected all the cavities between the foam pieces full of hot melt which, due to its bulk, fills the voids and bonds everything together. So now the Radjet nose is about as rigid again as it's ever been, although still not quite as pretty as it once was.

I've also wanted an easier way to fit the chubby 4-cell batteries as, in the past, I've had to forcefully ram these into the fuselage. Having some unused hatch hinges and some recently arrived, and long overdue, magnets I've decided to make a battery hatch a bit back from the canopy opening.

So far I've just fitted the hinges to the hatch, then I'll glue this to the fuselage and finally install the magnets, probably hot-melted in place and covered with felt tape to prevent them pulling out.

That will almost complete a substantial overhaul of the high-flying speedster, the last thing it needs in a canopy. If only they stocked spares for the 800...

Funfighterjet

...radical

A while ago the Radjet slowed down a bit, becoming somewhat pedestrian to fly. At this stage I decided to do a battery swap with the Rarebear and run the Radjet on 4S battery instead; the little buzzy being alarmingly fast flying on the high-voltage pack.

Recently, however, the Radjet suddenly regained its mojo and became seriously fast, carving up the sky in a most endearing manner. Unfortunately, this resurgence of speed was short lived with the Radjet reverting to its previous underwhelming state. The bearings in the stock motor being the main suspect.

However on my spares shelf I happened to have a spare Funfighter motor whichwas too good to resist as a parcel-filler with a previous purchase. Deciding this was the time, I set to stripping the old motor out of the Radjet.

This is a relatively simple process although, with the motor mount being bonded in as part of the rear fuselage section, you have to rip it out which is not great. However it came out easy enough nevertheless.

A few minor complications surfaced; the Rarebear motor requiring two sized mounting screws, M3's and M2.5's and, while I had some of the latter, I had none 30mm long so had to improvise somewhat. Also, the Funfighter motor comes with mini-bullet connectors, however I unsoldering the 3mm connectors from the stock motor and fitting these to the new unit solved that hiccup easily enough.

So the Radjet is now all set up and waiting for the glue to dry before I take it out and give it a good blast around the paddock. I'm looking forward to that...

Rarebear Best Battery

...finding the sweet spot

I'd bought the Rarebear along with the suggested "ballistic" upgrade battery, the 4S nanotech 45-90C, which promised incredible performance. They were quite right, except the little plane end up being so fast that I can't possibly fly it at that speed, spending most of the time just over half throttle and occasionally bumping it to around two-thirds.

However I have done a battery swap with the Radjet, flying that on the little 4S's and running the Rarebear on the 3S 1300's. This afternoon I flew the Rarebear twice, firstly on a 25-35C and then on a 25-50C. One wouldn't expect much difference, however the 25-50C is, in my opinion, the perfect battery for the Rarebear; it makes the plane significantly fast enough to keep you on your toes but remains controllable enough to make super-low flyby's at full throttle, which is how I like to fly my fast planes.

Anyway, so I think the swap will be permanent, the Rarebear happily swooping around on the 3S and the Radjet screaming around on 4S...

Radjet on 4S Battery

...giving the Radjet a bit of zing

I took the Radjet out this afternoon, having fun surfing a strong northerly breeze. Having depleted both batteries, and thinking the conditions a little extreme for the Phoenix, I pondered what i could do. Mentally reviewing my other spare batteries, one possibility presented itself.

The Radjet has been getting a bit slow lately; I'm not sure why but not being able to access the ESC or motor, I haven't been able to do any checks. My thought now was to try it out with one of the Rarebear's batteries; although diminutive they are four cell, which would give the Radjet a bit of a kick. Or make the ESC explode. Or melt the motor.

The 4S batteries are quite chubby, not unlike the Rarebear itself, so this was the first test. Amazingly enough, the battery fitted in the Radjet's fuselage, just. The next test would be when the power was connected. Actually, plugging in the battery had the ESC giving an extra beep, encouragingly recognising the extra cell in the battery.

Having given the controls a quick check, I flipped on the power somewhat hesitantly, not really knowing what to expect. The motor spun up, a little more energetically, then I cranked it up to two thirds and heaved the little plane skywards.

Hitting full power about halfway through launch, the faster prop speed was immediately obvious, as was the energy with which the Radjet was carving up the skies. While not massively fast, it was still considerably faster, and the return of its crackling propellor note was most welcome.

I think the 4S will be a regular occurrence with the Radjet from now on, turning the radjet back into the hooligan it always was...

Buzzy Planes Ahoy

...bobbing in the breeze

It was raining heavily this morning as I left, however I packed my two buzzy planes, the Radjet and Rarebear, along with a spare battery for each. Not knowing the weather, I wasn't liking my chances of getting any flying done that afternoon, but I having left home empty handed before, I've regretted it when the weather clears into a gorgeous afternoon.

Having a bootfull of planes was also a bonus as I ended up being very bored this afternoon, eventually abandoning my post and heading for the car park. The rain had cleared, but the sky was still overcast and a strong breeze was blowing from the southeast.

In this weather I take my buzzies - smaller wings mean they are less affected by turbulent conditions, and having constant high-speed prop-wash means that the effect of unsettled conditions is factored out.

First up was the Rarebear, giving it it's first test run since its aileron repair, which worked out pretty well with the balsa lining up nice and straight with the aileron. I also taped up both ailerons to avoid future issues.

The Rarebear launches very steep, with the motor, prop and high-performance batteries combining to give it flight characteristics that defy gravity. It also possesses remarkable agility, with a jaw-dropping roll rate as it carves perfect curves through the sky, in a quite remarkable manner.

Next I sent up the Radjet, still launching beautifully which is an absolute blessing, skimming low across the paddock, it's wings being constantly jostled by the breeze. I flew the Radjet until it's battery was depleted, bringing it round into the strong southeaster and easing it down for an almost vertical descent to landing.

By this time the breeze had cleared the sky into a fresh blue expanse, with just a few clouds dotted around, the sparkling white cumulus on the southern horizon looking like snow covered peaks out of the corner of the eye as I watched the planes streak across the sky.

With the field still clear of Friday footballers, I loaded the Radjet and Rarebear with fresh batteries and sent them up for another rounds of high-speed, full-throttle fun...

Radjet @ Speed

...battered but still kicking butt

The Radjet has had a tough life; crashed twice before I could get it in the air, then crashed on the first flight, and crashed numerous times after.

However, the Radjet's still a great little plane to fly, fast tough and with a sound to match it's flight attitude; low fly-past at high speed with the reverberating crackle of it's propellor shattering the still of the morning air...